The present invention relates to radiographic imaging in medical diagnostic equipment. It finds particular application in conjunction with vascular imaging systems and will be described with reference thereto however, it should be appreciated that the invention may also find application in conjunction with other equipment where a compact controller for select adjustable positioning of various system components is desired.
A typical vascular imaging system includes a gantry, a patient table, a source of x-radiation and a radiographic receptor. The gantry supports the source and receptor such that a radiation beam produced by the source is propagated along a path to the radiation receptor. The patient table is disposed in the path between the source and receptor. The gantry typically has one or more drive means which provide for controlled clockwise (CW) or counterclockwise (CCW) rotation of the source-receptor about a horizontal axis and separate CW or CCW rotation of the source-receptor about a vertical axis. The rotation of the source-receptor combination permits the portion of the patient under examination to be inspected from a variety of different selectable views. The patient table typically includes a drive means for variable, up-down, adjustment of the table height. The imaging system may also have a separate drive means for variable adjustment of the source to receptor distance for accommodating the table and patients of different size therebetween. The imaging system may also have a separate drive means for variable adjustment of shutters and irises, the adjustment providing for regulated control of the opening or closing of the shutters or irises for regulating the beam propagation path. Lastly, the imaging system may have one or more drive means for selectively moving and/or rotating one or more of a plurality of filters, disposed between the source and the patient table, for selectively filtering the x-radiation propagating from the source such that of appropriate radiation energy is received by the receptor.
In addition to drive means for regulated adjustment of certain linear functions the imaging system typically has one or more binary selectable functions where two or more states of said functions are chosen by the sequential engagement of the same function switch. One such binary function is a receptor magnification mode which selectively views a subset of the beam received at the receptor and displays said subset as a full view on a viewing means, such as a television screen. Still another binary function is a field light for providing a visual indication of where the beam path will enter the patient, said field light typically used to align the gantry. Lastly, some imaging systems may include a second source-receptor combination disposed about the patient for providing alternate selectable views of the same portion of the patient without having to reposition the first source-receptor combination.
At least one single pole single throw (SPST) switch is wired to each imaging system function. For drive means two (2) SPST switches or one (1) single pole double throw (SPDT) switch, is wired to each drive means to control the CW or CCW rotation of the select drive means. All of the switches are installed in a common control panel. Because each imaging system function is wired to and controlled by an individual switch the control panel tends to be relatively large and complex. It should also be appreciated that a wiring harness connecting the switches to their respective imaging system function tends to be relatively bulky because of the number of wires required to connect the controller to the imaging system.
A first attempt to overcome the objectionable size and complexity associated with a control panel having individual switches controlling the separate imaging system functions resulted in a plurality of individually engageable switches each having a common engagement means. One such arrangement includes a pivotal joystick having four (4) momentary contact switches disposed thereabout such that any one of said switches can be individually engaged by the pivotal movement of the joystick. A joystick-switch combination was provided for each of the separate functions to be controlled. One benefit of using the joystick-switch combination is that one such combination replaces two to four separate switches in the control panel with a corresponding reduction in the size and complexity of the panel. Another benefit of having the above joystick-switch combination is that the combination provides the occasion to logically associate imaging system functions. For example, rotational positioning of the source-receptor about the horizontal axis may be controlled by operation of a first joystick in the .+-.y direction while rotational positioning of the source-receptor about a vertical axis may be linked to operation of the first joystick in the .+-.x direction. It should be recognized that the number of joystick-switch combinations required is related to the number of different imaging system functions to be controlled thereby. The joystick-switch combination results in a smaller and less involved control panel than would be required if individual switches were disposed in the control panel face. The large number of joystick-switch combinations results however, in a control panel that is still relatively large and involved. Also, since each switch is still wired directly to the function it controls the number of actual switches has not decreased and the number of connecting wires remains the same as above.
For patient safety it is typically desirable to only engage one imaging system function at a time particularly those functions involving movement of the patient, the gantry or the receptor while the patient is dispose on the table.
In the above two embodiments the control panel is typically mounted to a floor rollable cart for rollable positioning thereof. The size of the panel and the wiring harness make the control panel difficult to move around the room for viewing the positioning of the imaging system or to move the panel and cable clear of the imaging system during imaging operation.
The present invention contemplates an improved control panel which integrates the functions of the above describe control panels into a compact, portable package that has a minimal number of switches and joysticks associated therewith.